I have a month to month lease do I have to sign a new lease every month and what are my rights

Month to month simply means you don't have a long term lease on the property and that either you or the landlord can end the relationship with short notice (usually 30 days). Have you read your current lease? It should spell out the details of how to end the lease.

I've been using this link a lot today. Renting - HUD (http://www.hud.gov/renting/)
Your rights depend on your location and a few other factors.

If I am not mistaken HUD only applies to residential, I would assume your speaking of a commercial lease since you posted under small business. The same answer would apply, your lease should spell out you are on a month to month as long as you pay each month and neither of you have notified the other of your intent to end the lease. Your rights would be the same as if you had a long term lease, but those also should be spelled out in your lease. No you do not need to sign a new lease each month.

Ir refers to a default lease. As if you had none. The only requirements are that you both are responsible for telling the other of any changes 30 days ahead.